Under organic cultivating condition,the author researched the influence of different rotation system which tomato was the succeeding crop on the soil chemical indexes,the soil microbe and the soil nematode.The results showed that: after one year′s experiment,the soil pH value of each treatment was decreased,the soil EC value had not changed distinctly.Except for available phosphorus content of control,other rotation system were improved in soil organic matter and soil available nutrient compared to the basic soil samples.Among them,the treatment of welsh onionradish-tomato was most in soil organic matter content and soil total nitrogen.Available nutrient content in soil of cauliflower treatment is most.The number of soil bacterium,azotobacter,actinomycetes were decreased significantly compared with basic soil samples.But the number of soil fungi was increased.The number of soil nematode of every treatment were increase.Among them,number of soil nematode was most but number of soil Root-knot nematode was least in chrysanthemum treatment.